The present invention relates to a sample holding apparatus for a sample such as a wafer which is to be carried repeatedly between a preliminary sample chamber and a main sample chamber, with the sample being exchanged in the preliminary sample chamber.
In known sample holding apparatus a mounted sample may be held by means which utilizes a human force, an exclusive electric drive source, or a pressure difference applied to the circumference of the sample.
In many cases, supply of a sample to a sample holding apparatus is made by an automatic supply means particularly when a semiconductor wafer or the like is to be held, and it is inconvenient to use a holding means for the mounted sample which relies on human hands. Moreover, even when such a holding means relies on an electrical means, there have been such unpreventable problems that its construction becomes very complicated, its cost is increased, and the like. Further, when the sample holding apparatus is inserted in a vacuum for use, it is impossible to use a holding means utilizing a pressure difference between the front and rear surfaces of the sample, and sample holding means utilizing static electricity has also not been used in practice for technical end economic reasons.